Passivus

Passivus is a Latin adjective meaning "passive" or "able to be suffered" and is used in grammatical terminology to name the passive voice in Latin. The adjective has the standard three-gender forms: passivus (masculine), passiva (feminine), and passivum (neuter). Etymology traces to pati "to suffer" with the suffix -ivus, reflecting the idea that the subject endures rather than performs the action.

In Latin grammar, passivus designates the passive voice and related participial forms (participium passivum). Passive verb forms are usually built from a passive participle combined with forms of esse (sum, es, est, sumus, estis, sunt) to express tense and aspect. The agent of the action may be expressed by the preposition a or ab followed by the ablative.

Latin also features a periphrastic passive, formed with esse and a participle of the gerundive, to express obligation or necessity (for example, librum legendum est, “the book must be read”).

In modern linguistic discussion, passivus is used chiefly as a label in studies of Latin syntax and in comparative work on voice systems across languages. Outside of grammar, the same Latin root appears in terms such as passivation in materials science, where a surface becomes chemically inert.

Thus passivus primarily denotes the Latin term for the passive voice and its related forms, with broader relevance to the study of grammatical voice.